Cable‑Supported PV Mounts Boost Wind Stability

New Chinese cable‑truss system raises critical wind speed to 36.8 m/s for 40 m spans

The two‑parallel cable‑truss mounting system unveiled by researchers at Chongqing University and PowerChina can sustain wind speeds of up to 36.8 m/s (≈ 133 km/h) on a 40‑metre span, far higher than conventional ground‑mounted structures. By splitting a single cable truss into two parallel trusses and adding π‑shaped purlins, the design lifts torsional stiffness without adding extra steel, offering a notable increase in flutter‑critical wind speed.

How the design works: geometry, pretension and sag control

The engineers built a mechanical model that treats the cable truss as the primary load‑bearing element, transferring PV module weight as a uniform distributed load. Key parameters – cable sag, truss height, and pretension – are iteratively tuned until gravity, wind pressure (0.654 kPa design load) and uplift are balanced. For the 40 m case, optimal pretension was 30 kN per primary cable, with sags of 2.23 m and 1.77 m. Increasing pretension raises both vertical and torsional natural frequencies, but beyond 30 kN the benefit plateaus, highlighting that geometry (especially truss height) is the dominant lever for stiffness.

Why torsional resistance matters for large‑scale solar farms

Typical single‑layer cable supports sway heavily under cross‑winds, limiting span length and forcing tighter module spacing. Space‑cable and traditional cable‑truss systems add lower cables or uplift cables, yet they still suffer weaker torsional resistance, leading to tilt, vibration and lower flutter wind‑speed limits. The new two‑parallel truss raises the torsional mode frequency, pushing the flutter limit to 36.8 m/s – roughly the speed of a Category 1 hurricane – making it suitable for rugged, hilly sites where wind gusts are severe.

Comparison with existing mounting solutions

System	Typical span	Wind‑induced displacement	Torsional stiffness
Single‑layer cable	≤ 15 m	High	Low
Space‑cable	≤ 25 m	Moderate	Moderate
Traditional cable‑truss	≤ 30 m	Moderate	Moderate
Two‑parallel cable‑truss (new)	40 m	Low	High

The new design achieves the longest span while keeping steel use modest compared with a single‑truss solution.

Market context: growing demand for flexible solar structures

Global demand for solar cable systems is expanding rapidly, with the market projected to reach US$ 3.1 bn by 2030, up from US$ 1.9 bn in 2023. As developers target remote, mountainous, or desert terrains, mounting systems that combine long spans, low weight and high wind resilience become a competitive advantage.

What it means for Israel

Israel’s solar market is driven by a residential feed‑in tariff of about ₪0.48/kWh and a typical turnkey cost of ₪3,150/kWp. On sloped sites, conventional ground mounts often require extensive earthworks and concrete foundations. A cable‑supported truss could reduce the amount of civil work required, potentially lowering overall project costs. Israel’s target of 30 % renewable electricity by 2030 will increasingly push utilities to develop solar farms on the country’s hilly regions, where wind gusts can be strong. The higher flutter‑critical speed of the Chinese system may help minimise wind‑related shutdowns and O&M impacts.

Forward look: scaling the technology

The researchers validated the concept with numerical simulations; the next step will be field trials on actual solar farms in China’s Sichuan basin and, eventually, overseas pilots. If the design proves cost‑effective at scale, it could encourage a shift toward lighter cable‑truss solutions in regions with challenging terrain.

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What it means for Israel (summary)

The cable‑truss system offers a way to lower civil‑work requirements on sloped sites, improve wind resilience, and could enhance the economics of solar projects.

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Frequently Asked Questions

• What is a cable‑supported photovoltaic structure (CSPS)? A CSPS uses tensioned steel cables to hold solar modules, allowing long spans and reducing the need for heavy concrete foundations.
• Why is torsional resistance important? Strong torsional stiffness prevents the structure from twisting under cross‑winds, which can otherwise cause module tilt, vibration, and early failure.
• Can the new two‑parallel truss be used in Israel’s climate? Yes. Its higher flutter‑critical wind speed (36.8 m/s) comfortably exceeds the strong gusts recorded in Israel’s desert and hilly regions, making it suitable for such sites.
• How does this affect project costs? By reducing foundation work, developers could achieve modest cost savings, improving overall project economics.
• When will the technology be commercially available? Field pilots are planned, after which manufacturers may offer kits for utility‑scale projects.
• Does the system impact solar panel efficiency? No. The mounting geometry does not shade the modules; it merely provides a more stable platform, preserving the panels’ rated output.

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Key Facts

• Critical flutter wind speed reaches 36.8 m/s for a 40 m span, far above typical design winds.
• Optimal cable pretension is 30 kN, with sags of 2.23 m and 1.77 m.
• Global solar cable‑system market is projected to hit US$ 3.1 bn by 2030.

Sources & further reading

• [PDF] Blue Book of China's Concentrating Solar Power Industry 2024
• [PDF] Blue Book of China's Concentrating Solar Power Industry 2024
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